Fixed several deprecation issues

Put __eq__ back to normal

Removed __init__ from deprecated i4xEncoder

Fixed _key for OpaqueKey

fix

Fixing usage key from deprecated string

Fixed some errors

replace fix for AssetLocation

add _from_deprecated_son to AsssetLocation

added replace for SlashSeperatedCourseKey

Bad reference in locations

offering deprecation fix and locations replace fix

Fixed bug in offering handling

Offering fixes

course_key kwarg check for LocationBase

Added Testing

Moved deprecation warning for i4xEncoder from default to __init__

Cleaned up offering handling and passed deprecation kwarg through deprecated replace functions

Removed Deprecation passing in replace and fixed version's deprecation warning